1. Field of the Invention
The present invention relates to apparatus and methods for producing patterned soft gelatin capsules.
2. Background of the Art
Capsules are solid dosage forms in which therapeutic agents are enclosed in a soluble gelatin wall. The wall can be made of either soft or hard gelatin. Soft gelatin capsules (xe2x80x9cSGCxe2x80x9d or soft gels) comprise a soft, globular, gelatin wall. The gelatin may be plasticized by the addition of additives such as glycerin, sorbitol, or a similar types of polyols. Soft gelatin capsules offer a convenient dosage form for the administration of drugs, nutrients, vitamins, foodstuff and cosmetics.
Commercially available SGCs come in a wide choice of sizes and shapes, e.g., they may be round, oval, oblong, tubular or suppository-shaped. These SGCs are formed by joining two identical halves to form a shell encapsulating a fill.
Upon ingestion by the consumer (or on contact with water), moisture causes the capsule to come apart at the seams where the two halves are joined thereby releasing the fill or contents of the capsule.
SGCs are generally prepared by one of two methods. The first method is known as the plate process. In this method, a set of molds is used. A warm sheet of gelatin is laid over a lower plate and the liquid fill is poured on it. A second sheet of gelatin is then placed on top followed by the top plate. The set is placed under pressure to form the desired capsule. The sheets of gelatin used to form the capsule may be colored or uncolored.
In 1933, Robert P. Scherer invented the rotary-die process. In this process, soft gelatin capsules are made by continuously casting two separate ribbons of molten or flowable gelatin into two separate rotating dies of an encapsulation machine to produce soft, elastic gelatin capsules. Dyes or other suitable coloring material can be added to the molten gelatin to produce soft gelatin capsules of various colors. In addition, if different dyes are added to the different molten gelatin masses then softgels with halves of different colors can be made. A more detailed description of the well known soft gelatin capsule art may be found in Ebert, xe2x80x9cSoft Elastic Gelatin Capsules: A Unique Dosage Form,xe2x80x9d Pharmaceutical Technology, October 1977 and in xe2x80x9cThe Theory and Practice of Industrial Pharmacyxe2x80x9d, Chapter 13, Lachman et al., published by Lea and Febiger, 1970. The rotary die process described in these references are incorporated herein by reference as being descriptive of the rotary die process to which the present invention is related.
The art also teaches applying identifying marks to the exterior surface of the capsule shell. Specific examples of known processes and machines used for applying some type of identification on softgels are shown, for example, in U.S. Pat. No. 2,449,139; Scherer U.S. Pat. No. 2,623,494; Scherer U.S. Pat. No. 2,688,775; Taylor U.S. Pat. No. 3,124,840; Hansen U.S. Pat. No. 3,203,347; and Vincent U.S. Pat. No. 3,333,031.
Scherer U.S. Pat. No. 2,623,494 relates to a banding machine for softgels. In this machine, the identifying band is applied to each individual capsule after the capsule is formed.
Scherer U.S. Pat. No. 2,688,775 shows a method for applying a brand to the exterior surface of a gelatin capsule.
Scherer U.S. Pat. No. 2,703,047 discloses a similar system of branding the filled capsules.
In Taylor U.S. Pat. No. 3,124,840, a printing element is provided in order to print on the gelatin strip prior to the formation of the capsule.
Hansen U.S. Pat. No. 3,203,347 shows a marking fluid that is printed on the gelatin ribbon used to make the softgels.
Vincent U.S. Pat. No. 3,333,031 shows dyeing of the gelatin strip before formation.
Scherer U.S. Pat. No. 2,596,176 teaches a method as well as an apparatus for striping gelatin capsules. In this method, gelatin capsule is grasped at its ends, successive contiguous parts of the capsule are abraded and, as the parts are being abraded, colors are applied.
German Patent No. 3,818,071 discloses processes for printing on the gelatin ribbons or strips used to manufacture soft gelatin capsules.
In the early 1960""s, R. P. Scherer in Canada produced and sold soft gelatin capsules made by the so-called xe2x80x9cswirlxe2x80x9d method. In the swirl method, two different colors of molten gelatin were fed into a single spreader box. The two different colors of gelatin were then allowed to intermingle or swirl and then to simultaneously flow through the opening at the bottom of the spreader box to form a patterned gelatin ribbon. However, because only a single spreader box was used, the exact nature of the pattern was difficult to control. Applicant has been unable to determine whether capsules made by the xe2x80x9cswirlxe2x80x9d method were ever commercialized within the United States.
The prior apparatus and methods for making soft gelatin capsules have failed to provide a convenient, easy to use, reproducible apparatus and method for producing patterned soft gelatin capsules, such as striped capsules. The prior methods have been unsatisfactory, such as those that merely printed patterns on the exterior surface of the gelatin ribbon, laborious, such as the abrasion method disclosed in Scherer U.S. Pat. No. 2,596,176, or lack reproducibility. There is a need in the art for an apparatus and method to solve these problems.
It is an object of the present invention to provide a convenient, easy to use apparatus useful for forming patterned soft gelatin capsules in a reproducible manner. It is also an object of the present invention to provide a process for making such patterned soft gelatin capsules that achieves the same benefits.
It is a specific object of the present invention to provide an apparatus for producing a patterned gelatin ribbon that is in turn useful for forming patterned soft gelatin capsules. The inventive apparatus includes a first spreader box for holding a first flowable gelatin mass. A second spreader box is then provided to hold a second flowable gelatin mass. The first type of gelatin and the second type of gelatin arc visually distinct, preferably by being different colors, such that the visual distinction between the two gelatins will form the pattern on the gelatin ribbon.
The second spreader box is positioned within the first spreader box. In this manner, an outer surface of the second spreader box and an inner surface of the first spreader box define a gap or opening through which the first gelatin may flow to form a base gelatin ribbon. The second spreader box has at least one opening through which the second gelatin flows onto a portion of the base gelatin ribbon. Since both gelatin types tend to preferably be molten or flowable at this point, they tend to meld together to form a patterned gelatin ribbon, which in turn may be used to form patterned soft gelatin capsules.
It is another specific object of the present invention to provide a process for producing a patterned gelatin ribbon that is useful for forming patterned soft gelatin capsules. In this process, a first gelatin mass contained in a first spreader box is flowed through a gap formed by an inner surface of the first spreader box and an outer surface of a second spreader box, the second spreader box being positioned within the first spreader box. When the first gelatin mass flows through this gap, it forms a base gelatin ribbon. The second gelatin mass, which is contained in the second spreader box, flows through an opening in the second spreader box onto a portion of the base gelatin ribbon, thereby forming a patterned gelatin ribbon. As with the inventive apparatus, the two types of gelatin are visually distinct from each other.
Other objects and embodiments of the present invention will be discussed below. However, it is important to note that many additional embodiments of the present invention not described in this specification may nevertheless fall within the spirit and scope of the present invention and/or the claims.